1. Field of the Invention.
The present invention relates to underwater signalling devices.
2. Description of the Related Art.
Applicant believes that the closest reference corresponds to U.S. Pat. No. 3,144,171 issued to E. Gagnan et al. However, it differs from the present invention because it utilizes the air contained in the tank to activate device 16 when actuated. Conceivably, the air pressure in the tank will determine whether the device will operate and to magnitude of the signal generated.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.